iphone 4s cannot connect to the server

I have been trying to set my iphone 4s up with groupwise mail and calendar. I have followed the instructions using microsoft exchange and the mobility server. It has worked on my ipad but not my iphone. The message, cannot 'connect to the server' appears and 70FB9178-576E-4CAA-A08E-F68D57B appears where inbox should be. I also get numerous no sender emails that cannot be deleted. The downloading 'wheel' keeps spinning its wheels until the cannot connect to server message appears.
I have tried deleting and reinstalling my account. Help!